Compressor



March 14, 1939. c. s. SORENSEN COMPRESSOR Filed Jan. 18, 1937 3Sheets-Sheet l March 14, 1939. c s soR s 2,150,347

COMPRESSOR Filed Jan. 18, 1957 3 Sheets-Sheet 2 March 14, 1939. sSQRENSQJ 2,150,347

COMPRESSOR Filed Jan. 18, 1957 s Sheets-Sheet 3 Patented Mar. 14, 1939UNITED STATES PATENT orrlce COMPRESSOR Clarence S. Sorensen, LosAngeles, Calif. Application January 18, 1937. SerialNo. 121,656 6Claims. (01. 2364-17) This invention relates to fluid handling machinesand relates more particularly to compressors. A general object of theinvention is to provide a practical, improved and very eflicientcompressor of the rotary type.

Another object of this invention is to provide a compressor or likemechanism of the rotary type and embodying reciprocable pistons that ischaracterized by having all its rotating parts dynamically balancedwhereby the inertia and forces set up by the rotation of the parts areall equalized or balanced.

Another object of this invention is to provide a compressor of thecharacter mentioned in which the rotating cylinder block and theeccentric rin for effecting operation of the pistons in the cylindersare both dynamically balanced and are individually supported forrotation to rotate with a minimum of friction and expenditure of power.

Another object of this invention is to provide a compressor of thecharacter mentioned embodying novel and very effective means forrotatably supporting the ring in eccentric relation to the axis of thecylinder block.

25 Another object of this invention is to provide a compressor of thecharacter mentioned embodying novel and very simple means forassociating the pistons with the eccentric ring that may allow relativeturning between the ring and the pistons and yet retain the pistons intheir proper relation to the ring.

Another object of this invention is to provide a compressor of thecharacter mentioned embodying a practical and long wearing valve meansfor controlling the inlet and discharge of the fluid.

Another object of this invention is to provide a compressor of thecharacter mentioned in which the valve means may be easily and quicklyregulated. 40 Another object of this invention is to provide acompressor of the character mentioned embodying simple means forreleasably connecting the main compressor shaft with the shaft of amotor or other power unit that permits the easy disconnection of themotor from the compressor proper.

The various objects and features of my invention will be fullyunderstood from the followin detailed description of typical preferredforms and applications of the invention. throughout which descriptionreference is made to the accompanying drawings, in which:

Fig. 1 is a central longitudinal detailed sectional view of thecompressor provided by this invention. Fig. 2 is a reduced end view ofthe compressor. Fig. 3 is a fragmentary'vertical detailed v sectionalview taken as indicated by line 3-3 on Fig. 1. Fig. 4 is a transversedetailed sectional view illustrating the cylinder block and the pistons.Fig. 51s a fragmentary side elevation with portions broken away toillustrate an alternative or modified mounting for the eccentric ring.Fig. 6 is a fragmentary vertical detailed sectional view taken asindicated by line 6-6 on Fig. 5 and Fig. '7 is a transverse sectionalview of the connection between the main shaft and the motor shaft takenas indicated by line 1-1 on Fig. 1.

The compressor provided by this invention includes, generally, a housingII), a shaft I extending through the housing It, a cylinder block I2 onthe shaft I, pistons i3 operable in the cylinders C of the block l2, aring |4 cooperating with the pistons l3 and supported in the housing IIIin eccentric relation to the cylinder block I2 to cause operation of thepistons, regulable valve means l5 for controlling the flow of fluid toand from the cylinders C and a power unit or motor l6 driving thecompressor shaft I.

- The housing I0 is a hollow structure containing the cylinder block l2and the ring l4 and supporting the shaft H and the valve means I5. Thehousing In in the preferred form of the invention includes a generallycylindrical main section l1 closed at one end by a bolted on plate l6and having an end wall I! at its other end. The end portion of thehousing section [1 adjacent the end wall I9 is reduced in diameter orheight as best illustrated in Figs. 1, 5 and 6. The housing of the motorI6 is secured to the end wall l9 as will be hereinafter described. Acomparatively large opening 26 in the end wall I! is closed by a plate2|. The plate 2| may be secured to the end wall [9 by suitable bolts-orscrews 22. The housing section I1 may. have suitable base or standardflanges 23. An annular and substantially cylindrical flange 24 projectsinwardly from the end wall IS. The upper portion of the flange 24 maymerge with the upper wall of the housing section II. The flange 24, theopening 20 and the plate 2| are oiiset or eccentric with relation to thelongitudinal axis of the housing Ill. The housing i6 is entirely closedand may contain a suitable lubricant.

,The shaft ll carries or drives the cylinder block I2 and extendslongitudinally and centrally through the housing It. The shaft extendsthrough an eccentric opening 25 in the plate 2| and projects from thehousing It for connection with the shaft of the motor. l6. A

tion of the shaft II. The bearing 26 may surround a reduced portion ofthe shaft II and may take end thrusts from the shaft in one direction. Aring 28 is secured in the opening ,25 and engages against the outer endof the bearing 26. The shaft II extends completely through the housingI6 to project through the end plate I8. In accordance with the inventionthe end plate [8 has a central tapered opening 29 receiving acorrespondingly tapered block 36 which in turn is provided with anopening 3| freely receiving the shaft II. The shaft II has a reduced endportion rotatably supported by a bearing 32 in the block 3!]. Thebearing 32 may engage against a shoulder 33 and a nut 34 on the shaft IIto take end thrusts from the shaft. The block 30 carries a suitable cap35 which closes the outer end of its opening 3| and retains lubricantfor the bearing 32. The block 30 is an element of the valve means I5. Atpresent it is believed suflicient to state that the valve block 30 issecured to the end plate I8 by studs or screws 36 threaded into openingsin a hub or boss 31 on the end plate I8. It will be noted that thecompressor shaft II is rotatably supported at its opposite ends by thebear ings 26 and 32.

The cylinder block i2 is the principal rotating element of thecompressor. The block I2 is preferably an integral member asillustrated. The cylinder block I2 rotates with the shaft II and issuitably fixed or keyed to the shaft adjacent the inner side of the endplate I8. A central opening 38 in the cylinder block l2 receives theshaft II. In the arrangement illustrated the shaft II has longitudinalgrooves 39 receiving threaded set pins 40 on the block I2 which fix thecylinder block to the shaft. The cylinder block I2 is bored to have thecylinders C. The cylinders C are radial openings being radial withrespect to the longitudinal axis of the shaft II. It is a feature of theinvention that the cylinder block I2 is dynamically balanced. Further,the block I2 is preferably light in weight and formed to remain as coolas possible. The cylinder block I2 is provided with a multiplicity ofcircumferentially spaced parts 4| projecting radially outward relativeto its axis of rotation. The radially projecting parts M are equally orsymmetrically spaced and the cylinders C are provided in the parts M. Inthe case illustrated the'ra'r six equally spaced cylinder parts 4i eachprovided with a cylinder C. The cylinders C extend into the outer endsof the cylinder parts 4| being in the nature of cylindrical sockets orbores closed at their inner ends and open at their outer ends to receiveor carry the pistons I3. The cylinders C, of course, are of equal size.It will be noted that the cylinder block I2 is a simple light-weightmember and is diametrically balanced so that its rotation imposes aminimum stress on the shaft II and the shaft bearings.

The pistons I3 are provided to reciprocate in the cylinders C to pump orcompress the fluid handled by the machine. In practice the pistons I3may be simple structures as illustrated. The pistons I3 are closed attheir inner ends by integral imperforate heads and suitable rings 42 areprovided on the pistons I3 to slidably seal with the walls of thecylinders C. The outer ends of the pistons I3 are closed by plug-likeheads 43. The heads 43 have radial annular flanges 44 opposing the outerends of the pistons I3. In accordance with the invention the heads 43are adjustably secured to the pistons I3. The heads 43 are threaded intothe pistons I 3 and laminated shims 43 are provided between the flanges44 and the outer ends of the pistons I3. The pistons I3 and their heads43 may be adjusted with respect to one another by varying the thicknessof the shims 45. Shoes 46 are provided on the piston heads 43 forcooperating with the ring I4. The shoes 46 may be integral with thepiston heads 43 and have curved convex outer surfaces 41 for cooperatingwith the interior of the ring I4 as will be subsequently described.

The ring I4 is provided to cooperate with the shoes 46 of the pistons I3to effect the operation of the pistons. The active portion of the ringI4 surrounds the cylinder block I2 while the supporting portion of thering I4 extends into the internal housing flange 24 to be supportedtherein. The ring l4 includes a cylin drical tubular section 48surrounding the cylinder block I2 and having a finished cylindricalinternal surface 49 for slidably cooperating with the surfaces 41 of theshoes 46. The ring I4 further includes a disc-like section 50 having acylindrical tubular sleeve 5I extending axially into the housing flange24. The ring section 48 may be attached to the section 50 by suitablescrews 52.

As described above, the flange 24 is eccentric relative to the axis ofthe housing I and the sleeve is rotatably supported in the flange 24 sothat the ring I4 is rotatable about an axis parallel with and spacedfrom the axis of rotation of the cylinder block I2 and the shaft II. Inthe construction illustrated in detail in Fig. 1 the sleeve 5I isrotatably supported by an antiiriction bearing 53 in the inner portionof the flange 24 and a somewhat smaller bearing 54 in the opening 23 inthe housing end wall I9 at the outer end of the flange 24. The inner endportion of the flange 24 may have an inwardly extending rim providedwith a groove 56 carrying the bearing 53. The bearings 53 and 54 maycooperate with shoulders 51 and 58, respectively, of the sleeve 5| toreceive end thrusts from the ring I4.

It will be observed that the ring I4 just described is supported in thehousing I 0 for free rotation and has its cylindrical internal surface43 engageable by the shoes 46 of the pistons I3 which engagement maycause rotation of the ring I4 when the cylinder block I2 is rotating. Itis believed that it will be apparent how the ring I4 having its axis ofrotation spaced from the axis of rotation of the cylinder block I2cooperates with the piston shoes 46 to successively cause inwardmovement of the pistons in the cylinders. The outward movement of thepistons is caused by centrifugal force or fluid pressure in thecylinders; or both. It will be seenthat by varying the thickness of theshims 45 the innermost positions of the pistons I3 relative to thebottoms of the cylinders C may be adjusted or regulated as found mostdesirable. It is important to note that the above described ring I4 issymmetrical and dynamically balanced and rotatably supported in such amanner that it imposes a minimum of stress on the bearings and housingparts.

The invention provides simple means for loosely connecting the pistonsI3 with the ring I4 to prevent the pistons from falling inwardly in thecylinders C when the operation of the compressor is suspended. Thismeans includes a hook-like I inders C.

scoping portions of the boss 31- a I and has communication with theamal'port-;6l'.- The port 62 is curved concentric with the axis of r theshaft II and is of substantial length and member 18 attached to theouter end of each piston shoe 48 by a screw or bolt 18. Themembers 16extend outwardly at the end of the ring section 48 and each has a finger'll projecting axially at the outer periphery of the ring section. Themembers 15 do not engage the end of the ring section 48. The fingers 11are normally clear of the periphery of the ring section 48 but mayengage aga nst the ring section to prevent the pistons l8 from fallingor moving inwardly in the cylinders C when the compressor is stopped.

The valve means I6 is provided to control the admission and exhaust ofthe fluid from the cyl- It is a feature of the invention thatthe valvemeans l5 includes a minimum number of simple parts. The means I6includes the valve block 30 mentioned above. The tapered block 36 istightly clamped in the tapered opening 29 by the studs or bolts 36" totightly seal with the wall of the socket. A sealing washer or ring 59may be clamped between opposing" shoulders of the block 30 and thesocket 28 to assure aperfect seal. A suction or inlet line 68communicates with a port 6| extending i5ito theeboss' 31 of the endplate l8. gi urged ocircuhiferebz. tial port 62extends-througlilfieengagingte radial extent so thatthefluid;;flowingthere'- through serves to cool the r8 widtfifand curvedconcentric port 6311') rd'fi ced length is provided in the inner face64of the valv block 38 and has extensive communicationwith; the port 62.The port 63 is preferably slightly less than 180 in circumferentialextent. The inner surface or face 64 of the valve block 30 is finishedand smooth. Webs 65 may extend through the port 62 to connect the partsof the block 38 separated by the port.

An outlet or discharge line 66 communicates with a radial port 61extending into the boss 31. The port 61 continues through the boss 31and the block 38 to have its inner end at the inner surface 64 of thevalve block. The inner end of the port 61 is..of' the same widthas theport 83 and has the same curvature as the port 63. The discharge port'GTis somewhat shorter than the inlet port'63 being only substantially-90in circumferential extent at the inner surface 64 of the valve block 30.The discharge port 61 does not occur in opposite relation to the port 63but has one endin spaced adjacent relation to an end of the port 63.This relationship is clearly illustrated in Fig.3 of the drawings.

The valve means l5 further includes a valve block or member 68 arrangedin a socket 68 in the cylinder block ii to have its outer end oppose theinner surface 64 of the block 38. In accordance with the invention themember 68 has limited axial movement in the socket 69 but is made toturn with the cylinder block l2. One or more pins 10 project from theinner wall of the socket 69 and slidably fit openings II inthe member 68to cause the member to turn with the cylinder block. Spring means isprovided to urge the member 68 outwardly to have its outer end insealing contact with the surface 64 of the valve block 30. In thepreferred construction illustrated a plurality of spaced bores 12 isprovided in the bottom of the socket 68.. The bores 12 receive coiledsprings 13 which engage against the inner end of the valve member 68 tohold the member outwardly so that its outer and seals against thesurface 84 of the block 88. Ports 14 extend from the inner ends of thecylinders C to the outer face or end of the valve member 68. A singleport I4 communicates with each cylinder C. The ends of the ports 14 atthe face of the block 68 are in the same rotative positions as theirrespective cylinders C and are in a circumferential series tosuccessively register with the ports 63 and 61 in the valve block 80. v

The rotative positions of the ports 63 and 61 in the face 64 of thevalve block 30 are related to the eccentricity of the ring 14 in such amanner that the port I4 of a cylinder C communicates with the'inlet port63 during the out stroke of the piston [3 in the cylinder and comes intocommunication with the outlet port 81 when the piston is in the majorfinal portion of its inward stroke after the gas has been compressed thedesired extent. The invention provides novel and very effective meansfor regulating the valve 'means |5, th p1s foradjusting the rotativeposi- 1 the desired operationof the machine. the bipola The valveadjusting means includes an abutment 18 on the block- 30. The abutment18 may project outwardly from the block 30 adjacent the boss 31. Spacedlugs 18 project outwardly from the end plate l8 to be in spaced relationfrom the opposite sides of the abutment I8. A screw is'threaded throughan opening in each lug l9 and the screws are adapted to engage againstthe abutment 18. The screws 88 engaging against the abutment 18 normallyprevent turning of the valve block 30 and thus retain the valve block inits adjusted position. Lock nuts 8| may be provided on the screws 88 toset the screws in their adjusted positions. The openings 36 in the block30 which receive the studs 36 are in the nature of slots or curvedopenings whereby the block 30 may have limited turning movement when thenuts 36'' onthe studs 36 are loosened.

It will be apparent how the valve block 30 may be turned or adjustedfollowing the loosening of the nuts 36 by backing off one screw 88 andtightening in the other screw 80. After such adjustment the lock nuts 8|may be employed to lock the screws 88 in place and the nuts 86 may betightened down. Turning or adjustment of the valve block 30 by theadjustment means just described changes the rotative position of theports 63 and 61 and therefore changes the times during which thecylinder ports 14 communicate with the ports 63 and 61. The ports 63 and6'! are, of course, related or spaced so that the cylinder ports 14 areout of communication with both of them at the ends of the pistonstrokes.

The motor I6 is provided to drive or rotate the compressor shaft II. Theparticular motor "5 illustrated is a sealed induction motor comprising ahousing 83, an armature 84 and a field 85. The present invention is notprimarily concerned with the armature 84 of the field 85 of the motor.The armature 84 is carried by a shaft 86. The motor housing 83 issubstantially cylindrical and is entirely closed or sealed. An integralwall 81 closes the outer end of the housing 83. A suitable bearing 88 iscarried in a socket 88 in the housing wall 81 to rotatably support theend of the motor shaft 86. The inner end of the motor housing 83 isconnected with the end IQ of the compressor housing III by a flange andbolt concompressor. ,A manifold 92 extends around the motor housing 93and is adapted to-carry water orother cooling medium to cool the motor.The

cooling medium may be supplied to and carried I from the manifold 92 bysuitable lines as.

' The invention provides an effective readily re;

leasable connection between the compressor shaft l I and the motor shaft86. The motor shaft 86 is provided with an axial socket 55 in its innerend which receives the end portion of the compressor shaft ii. Thesocket 94g-is provided with longitudinal splines 95 which cooperate withgrooves 96 in the compressor shaft I I. The shaft II may have a reducedpilot portion 91 fitting a correspondingly reduced portion of the socket94. The shafts II and 86 may be quickly connected by sliding the shaft96 onto the end portion of the shaft II so that the splines 95 arereceived in the grooves 96. The splines 95 cooperating with the grooves96, of course, transmit rotation between the shafts. The connection justdescribed permits the entire motor I6 to be easily removed from thecompressor without disturbing any parts of the compressor. In the eventthat the motor I6 requires replacement or repair the flange and boltconnection 99 may be released whereupon the entire motor IG may bebodily moved away from the housing I9. The splines 95 slide out of thegrooves 99 allowing the shaft 86 to freely disconnect from the shaft II.In this manner the motor I6 may be disconnected from the compressorproper without disturbing any parts of the compressor.

Figs. 5 and 6 of the drawings illustrate a form of the inventionembodying an alternative or modified means for rotatably supporting thering I4. In this form of the invention the tubular internal flange 24 ofthe housing I is provided with a plurality of pairs of spaced cars 98.The cars 98 project inwardly in the flange 24 and are spaced apartaxially with respect to the axis of the machine. The pairs of cars 98are preferably equally spaced about the interior of the flange 24. Ashaft 99 is carried by each pair of ears 98. The shafts 99 may bepressed or otherwise secured in openings I09 in the cars 98 and areparallel with the axis of the ring sleeve Suitable anti-frictionbearings IDI are carried by the end portions of the shafts 99 to havesupporting cooperation with the sleeve M. The bearings IIlI may engageagainst the outer sides of the ears 99 and shoulders I92 and I 93 on thesleeve 5| for the transmission of end thrusts. It is believed that itwill be apparent how the spaced sets or pairs of anti-friction bearingsIIlI support the ring I4 for free independent rotation.

It is believed that the operation of the compressor will be understoodfrom the foregoing detailed description. The motor I6 drives or rotatesthe shaft II which in turn rotates the cylinder block I2. The cylinderblock I2 is symmetrical and dynamically balanced so that its rotationimposes a minimum of stress on the shaft II and its bearings. As thecylinder block I2 rotates within the eccentrically disposed ring I4 theshoes 46 cooperating with the interior of the ring cause the pistons I3to be successively moved inwardly in the cylinders C. The centrifugalforce on the pistons I3 and perhaps the fluid pressure in the cylindersC successively move the pistons outwardly in the cylinders C. In actualoperation the members I5 do not cooperate with the ring section 48 tocause the outward movement of the pistons in the cylinarcane? ders. Whenoperation of the compressor Is commenced the engagement of the shoes 48with the internal surface 49 of -the ring I4 may be in the nature of asliding engagement and the ring may tend to remain stationary. However,the engagemerit of the. shc'eswith the interior of the ring it willultimately result in rotation of the ring it with the cylinderblock-l2aHowevenas the ring- I9. is independently's'upportedfor rotation about anaxisspacedfrom the axis of rotation of the cylinder block I2 itsoperation remains the same irrespective of whether it rotates or remainsstationary. 1 The ring I4 is a symmetrical dynamically balancedstructure and its rotation imposes a minimum of stress and strain on itsbearings 53 and 54 and the housing parts.

The valve member 68 turns with the cylinder block I2 and the cylinderports 14 successively move across the inlet port 63 and discharge port61 in the end face 64 of the block 39. As described above, the ports 63and 61 are related to the position of the ring I4 so that the cylinderports I4 are in communication with the inlet port 63 duringsubstantially the entire out strokes of the pistons I3 and come intocommunication with the discharge ports 61 when the pistons I3 havecompleted a. portion of their inward strokes and remain in communicationwith the discharge port 61 during the remainder of the stroke so thatthe fluid under pressure is discharged through the port 61 and the line56. The screws 89, may upon loosening of the nuts 36 and 8I be employedto change the rotative position of the valve block and thus adjust therotative position of the ports 63 and 61 to properly regulate the actionof the compressor.

It will be noted that the valve means I5 embodies a minimum number ofworking parts. The member 68 engages against the surface 64 of the block30 and is held in sealing contact therewith by the springs I3. Themember 68 and the block 30 constitute the only engaging and moving partsof the valve means I5. The compressor shaft II is dependably supportedat its opposite ends by the bearings 26 and 32 while the ring I4 iseffectively supported at spaced points by the bearings 53 and 54. Thusthe principal rotating elements of the compressor are efiectivelysupported by sets of spaced bearings. The compressor is compact and yethas a substantial capacity. There are a minimum of wearing and workingparts embodied in the machine. The shims 45 constitute an easy means ofregulating contact between the pistons I3 and the ring I4 and foradjusting the clearance of the pistons in the cylinders 0.

Having described only typical preferred forms and applications of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any variationsor modifications that may appear to those skilled in the art or fallwithin the scope of the folowing claims Having described my invention, Iclaim:

1. A mechanism of the character described including a housing, a shaftextending through the housing, a tubular internal flange formed on thewall of the housing surrounding the shaft in spaced relation thereto, acylinder block in the housing fixed to the shaft and having cylinders,pistons operable in the cylinders, valve means for controlling the fluidfiow to and from the cylinders, a ring surrounding the block forcooperating with the pistons, a sleeve on the ring extending into saidflange, an annular series of with the said inlet circumferentiallyspaced bearing shafts in the said flange, and anti-friction hearings onthe bearing shafts cooperating with the sleeve to support the ring forrotation about an axis spaced from the axis of the cylinder block.

2. A mechanism of the character described including, a housing havingspaced opposite end walls, a rotatable shaft extending through thehousing, bearing means carried by said end walls for rotatablysupporting the shaft, a rotor fixed to the shaft in the housing andhaving radial cylinders and having cylinder ports communicating with thecylinders, pistons in the cylinders, a ring rotatably supported in thehousing in eccentric relation to the shaft and cooperating with thepistons, two elements one a block supported by the housing and having aninlet port and an outlet port both extending to the exterior of thehousing, the other a part carried by the rotor and having portscommunicating with the cylinder ports and adapted to register with thesaid inlet during the out strokes of the pistons and adaptedto registerwith the said outlet port during only portions of the in strokes of thepistons, both of said elements being in surrounding relation to .theshaft, and means for urging one element against the other.

3. A mechanism of the character described ineluding, two elements one ahousing, the other a rotating rotor having radial cylinders, pistons inthe cylinders, a ring rotatably supported in the housing in eccentricrelation to the shaft and cooperating with the pistons, a blocksupported by one of the elements for limited turning movement and havingan inlet port and an outlet port the outlet port being of less extentthan the inlet port at a face of the block, the rotor having portscommunicating with the cylinders, a member carried by the other elementand having ports communicating with the cylinder ports, the member beingpressed against said face so that its ports are.adapted to successivelyregister and outlet ports, and means for regulating the rotativeposition of the said block, the said means including a fixed abutment,and screw ports on the said block cooperating with the abutment.

4. A of the character described includin a housing, a rotatable shaftextending through the housing, a rotor fixed to the shaft in the housingand having radial cylinders, pistons in the cylinders. a ring rotatablysupported in the housing in eccentric relation to the shaft andcooperating with the pistons; a block supported by the housing forlimited turning movement and having an inlet port and an outlet port,said inlet and outlet ports extending to the exterior of the housing therotor having ports communi-' eating with the cylinders and adapted tosuccessively register with the said inlet and outlet ports, and meansfor regulating the rotative position of the said block, the said meansincluding an abutment on the housing, lugs on the said block at oppositesides of the abutment and screws on the lugs cooperating with theopposite sides of the abutment.

5. A mechanism of the character described including, a housing having anend wall with an opening, a rotatable shaft extending through thehousing, a rotor 'fixed to the shaft in the housin and having radialcylinders, pistons in the cylinders, a ring rotatably supported in thehousing in eccentric relation to the shaft and cooperating with thepistons, a block supported in said opening and having an inlet port andan outlet port, said ports extending to the exterior of the housing, anda part carried by the rotor to have part having ports inders and adaptedto sucessively communicate with said inlet and outlet ports, the saidinlet port being of large circumferential extent whereby the fluidtherein serves to cool the block and the adjacent parts. 6. A mechanismof the character described including, a housing, a rotatable shaftextending through the housing, a rotor fixed to the shaft in the housingand having radial cylinders, pistons in the cylinders, a ring rotatablysupported in the housing in eccentric relation to the shaft andcooperating ,with the pistons. the housing having a tapered socketco-axial with the rotor, a tapered block the block in the socket andallowing turning of the block, the block having an inlet port and anoutlet port, a spring-urged member carried by the rotor and with theblock, the rotor and member having ports communicatin with the cylindersand adapted to successively communicate with the inlet and outlet ports,and means normally holding the block against tuming and operable to turnthe block.

. a soanusnu.

in the socket, means securing-

